1. Field of the Invention
The present invention relates to a method and a device for processing parts, preferably made from timber-derived materials, and correspondingly painted or coated timber parts.
2. Prior Art
Timber-derived materials are used in all kinds of applications, especially, for example, in the furniture industry. The timber-derived materials used there are usually coated or painted, but the term “coating” is used herein as a generic term to cover painting as well as powder coating and the like. The purpose of painting or coating is to impart an aesthetically appealing surface to the timber-derived materials.
Demands in this regard have grown increasingly in recent years, as furniture designs with, for example, high-gloss surfaces, impose much greater demands on the coating or painting. Accordingly, the methods for manufacturing such furniture entail great outlay, since diverse individual process steps, such as sanding the wood surface, intermediate sanding of already partially painted or coated surfaces and final polishing of the coated or painted surfaces, are required. Moreover, in certain circumstances, several coats or paint layers may be required, with the result that the overall process entails very great outlay.
This also applies to the recently very commonly employed wood fiber materials, such as medium density fiber board (MDF) panels, which also need appropriate pretreatment, for example, in order that fibers protruding from the surfaces may be removed prior to coating or painting.
In the prior art, this is usually achieved by sanding processes, in which abrasive media, such as corundum and similarly abrasive elements, are arranged on a carrier, such as sandpaper or a sanding wheel, so as to be moved over the surface by means of the carrier in a rotating movement or any other form of movement. The pressure exerted by means of the carrier causes the abrasive media to remove material from the surface of the part to be treated. When the abrasive media are of a suitable grain size, the outcome can be a fine, smooth and flat surface.
Similarly, painted or coated surfaces can be processed with corresponding polishing media, which in turn contain abrasive particles or powder which are taken up in an auxiliary medium, such as a liquid or a pasty medium, and are moved across the surface by means of flexible carriers, such as cloth or felt discs and the like, such that, again in turn, the abrasive media can effect corresponding material removal.
Such methods especially entail very high outlay because, for the sanding or polishing steps, the corresponding part to be processed must be arranged in a defined manner relative to the sanding or polishing device, a fact which usually entails laborious handling of the corresponding part, since a change of fixture is needed relative to the coating or paint processing. The part must usually be removed from a fixture used for the coating or painting and installed in a fixture suitable for the sanding or polishing processes and, after sanding or polishing, again be removed and installed in a different fixture, a fact which leads to highly laborious handling. Consequently, there is hardly any scope for continuous processing operations, that include coating and painting operations and the sanding and polishing operations, in a so-called inline installation.